Instant messaging systems allow users in a group to see whether members of the group are logged on to the messaging system, and allow users to chat with each other using a text-based system. Collaborative tools such as NetMeeting, similarly, allow users to see who is currently active in the system and allow the users to join a conference and share documents. Email and voice mail systems allow users to send pointers to documents and attach messages in the form of text and/or voice.
Currently, users are forced to choose between synchronous communication and asynchronous communication. Synchronous communication (e.g., phone calls, chat and the like) requires the other users to be present at the same time and is intrusive in nature because a caller or a chat session participant interrupts the other users with a request to communicate immediately. Asynchronous communication allows users to respond at their leisure, but introduces delay and is narrow in bandwidth. Commonly, users send email messages to other users and ask them to phone them back in an attempt at establishing a polite request for communication. Besides being cumbersome, this approach has two major difficulties; (a) there is no indication as to the availability of the originator (if the email is read hours later, is the originator still at work?), and (b) the responder pays for the phone call, not the person who requested the call.